(CNN) --The process to extradite Joran van der Sloot from Peru to the United States to face criminal charges has begun, according to Maximo Altez, van der Sloot's Peruvian attorney.

Peruvian judges in January sentenced the Dutchman to 28 years in prison for the murder in 2010 of Stephany Flores. He is also the prime suspect in the disappearance of American Natalee Holloway. U.S. authorities want to try van der Sloot on charges of extortion and wire fraud in the Holloway case.

According to court documents obtained through Altez, a Peruvian judge has approved a U.S. request for provisional detention. This is the first step in the extradition process between Peru and the United States. The document says a formal extradition request has yet to be submitted, but will follow. Read more;